(1) Field of the Invention
The present invention relates to a bacterial method and compositions which utilize two (2) different plasmid modified strains of Pseudomonas putida together to more effectively degrade chemical compositions including mixed aliphatic and aromatic hydrocarbons, especially in the waste compositions. In particular, the present invention relates to a method and compositions which utilize a first Pseudomonas putida which contains first and second plasmids encoding for camphor (CAM) and toluene (TOL) degradation and a second Pseudomonas putida which contains a third plasmid which encodes for naphthalene (NAH) degradation as a result of mating of the plasmids into parent strains.
(2) Prior Art
Aliphatic and aromatic hydrocarbons are degraded in nature as shown in the following references: U.S. Pat. No. 4,452,894 to Olsen et al; U.S. Pat. No. 4,594,003 to Vandenbergh; Vandenbergh, P. A. and A. M. Wright, Appl. Environ. Microbiol. 45: 1953-1955 (1983); Vandenbergh, P. A., C. F. Gonzalez, A. M. Wright and B. S. Kunka, Appl. Environ. Microbiol. 46: 128-132 (1983); Vandenbergh, P. A., R. H. Olsen and J. F. Colaruotolo, Appl. Environ. Microbiol. 42: 737-739 (1981); and Vandenbergh, P. A., and R. L. Cole, Appl. Environ. Microbiol. 52: 939-940 (1986). The useful application of bacteria to the environment to degrade toxic waste has been previously demonstrated by U.S. Pat. No. 4,594,003. However, due to the complex nature of chemical waste sites many hydrocarbons are present and it is difficult to provide a mixture of many different strains having individual hydrocarbon degrading characteristics to handle a complex mixture of the hydrocarbons.
Through the use of bacterial genetics, it has been possible to improve the biochemical properties of hydrocarbon degrading strains and reduce the number of different strains by means of introduction of plasmids into the strains. Strains have been previously produced that contain multiple hydrocarbon degrading plasmids as shown by Chakrabarty et al U.S. Pat. No. 4,259,444. These modified strains grow slowly in a fermenter with subsequent poor growth yields in terms of numbers of bacteria per ml produced in the growth medium and thus are not practical to commercialize. Plasmid incompatibility and spontaneous curing of plasmids also reduce the utility of these strains.
OBJECTS
It is therefore an object of the present invention to provide a unique mixture of Pseudomonas putida strains which rapidly degrades chemical compositions particularly wastes found in the environment. Further it is an object of the present invention to provide a method for degrading the chemical compositions using this mixture. Further still it is an object of the present invention to provide strains of Pseudomonas putida which grow rapidly to high numbers per ml. These and other objects will become increasingly apparent by reference to the following description and the drawings.